1. Field of the Invention
This invention is particularly concerned with ventricular assist devices for supplementing the cardiac output in a failing heart in sinus rhythm or for effecting increased cardiac output in the dysrhythmic heart, as well as in the event of total arrest or ventricular fibrillation.
2. Description of the Prior Art
It is known that the device of my prior U.S. Pat. No. 4,690,134 of Sep. 1, 1987 has been proposed to fit a human heart to apply a rhythmic pulsating pressure to keep the heart pumping for maintaining a supply of blood at the needed pressure to effect circulation. Somewhat similar devices have been disclosed by Vineberg in U.S. Pat. No. 2,826,193 of Mar. 11, 1958, by Snyders in U.S. Pat. No. 4,690,134 of Sep. 1, 1987, by Parravicini in U.S. Pat. No. 4,536,893, and in the U.S. Pat. No. 3,034,501 of Hewson of May 15, 1962 for an inflatable heart massager in the form of a flexible distendable resilient bag with inner and outer walls of differing thickness, with the outer wall being thicker to minimize relative distending of this wall. It is also disclosed in Hewson that the interior of the bag can be divided into two chambers so each can have its own supply of pressure fluid.